The present invention relates to a gear arrangement for a motor vehicle, especially a tractor or other agricultural or construction vehicle. The arrangement is of the type comprising a range gear in cascade with a creep gear, and means for selectively driving the range gear directly or through the creep gear.
Gearboxes are known from DE AS No. 1 285 338 and from EP No. 0 024 100 with driven bevel gears and forward and reverse clutches for coupling these gears to a clutch shaft. In these known gearboxes, the range gear is on the output shaft-line of the change-speed gear and no provision is made for a creep gear.
Since it is highly desirable to incorporate a creep gear in tractors in order to provide extremely low tractor speeds, such a gearbox of the aforementioned type has been proposed and is described in our European patent application EP No. 82 304 972 1. In this prior application, the clutch shaft is rotationally fixed to the input member of the range gear and the forward and reverse clutches couple two driven bevel gears, respectively, to the clutch shaft for normal forward and reverse drive. A third clutch is provided for coupling the reverse bevel gear to the creep gear. The reverse bevel gear is chosen because the creep gear affects a reversal of the sense of rotation of the changespeed gear input shaft relative to the clutch shaft.